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><H1
CLASS="SECT1"
><A
NAME="CACHEMODE"
>5.2. Cache mode storage</A
></H1
><A
NAME="AEN3443"
></A
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHEMODE-INTRO"
>5.2.1. Introduction</A
></H2
><P
><TT
CLASS="LITERAL"
>cache</TT
> words storage mode is able to index and search 
quickly through several millions of documents.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHEMODE-STR"
>5.2.2. Cache mode word indexes structure</A
></H2
><P
>The main idea of cache storage mode is that word
index and data for URL sorting is stored on disk rather than in a <SPAN
CLASS="APPLICATION"
>SQL</SPAN
> database. Full URL information
however is kept in <SPAN
CLASS="APPLICATION"
>SQL</SPAN
> database (tables <TT
CLASS="LITERAL"
>url</TT
> and <TT
CLASS="LITERAL"
>urlinfo</TT
>). 
<A
NAME="AEN3457"
></A
>
Word index is divided into number of files specified by <B
CLASS="COMMAND"
>WrdFiles</B
> command (default value is 0x300).
<A
NAME="AEN3461"
></A
>
URLs sorting information is divided into number of files specified by <B
CLASS="COMMAND"
>URLDataFiles</B
> command (default value is 0x300).
<DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
>Beware: you should have identical values for WrdFiles and URLDataFiles commands in all your configs.</P
></BLOCKQUOTE
></DIV
></P
><P
> Word index is located in files under <TT
CLASS="FILENAME"
>/var/tree</TT
> directory of <SPAN
CLASS="APPLICATION"
>DataparkSearch</SPAN
>
installation. URLs sorting information is located in files under <TT
CLASS="FILENAME"
>/var/url</TT
> directory of 
<SPAN
CLASS="APPLICATION"
>DataparkSearch</SPAN
> installation. </P
><P
><A
NAME="AEN3473"
></A
><A
NAME="AEN3476"
></A
>
<SPAN
CLASS="APPLICATION"
>indexer</SPAN
> and <SPAN
CLASS="APPLICATION"
>cached</SPAN
> use memory buffers to cache some portion of cache mode data before flushing it to the disk.
The size of such buffers can be adjusted by <B
CLASS="COMMAND"
>CacheLogWords</B
> and <B
CLASS="COMMAND"
>CacheLogDels</B
> commands in <TT
CLASS="FILENAME"
>indexer.conf</TT
> and <TT
CLASS="FILENAME"
>cached.conf</TT
> 
config files respectively. Default values are 1024 for <B
CLASS="COMMAND"
>CacheLogWords</B
> and 10240 for <B
CLASS="COMMAND"
>CacheLogDels</B
>.
An estimation of total memory used for such buffers can be calculated as follow:</P
><PRE
CLASS="PROGRAMLISTING"
>Volume = WrdFiles * (16 + 16 * CacheLogWords + 8 * CacheLogDels), for 32-bit systems
Volume = WrdFiles * (32 + 20 * CacheLogWords + 12 * CacheLogDels), for 64-bit systems</PRE
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHEMODE-TOOLS"
>5.2.3. Cache mode tools</A
></H2
><P
>There are two additional programs
<TT
CLASS="FILENAME"
>cached</TT
> and <TT
CLASS="FILENAME"
>splitter</TT
> used in <TT
CLASS="LITERAL"
>cache mode</TT
> indexing.</P
><P
> <TT
CLASS="FILENAME"
>cached</TT
> is a TCP daemon which collects word
information from indexers and stores it on your hard disk. It can operate in two modes, as old
<TT
CLASS="FILENAME"
>cachelogd</TT
> daemon to logs data only, and in new mode, when <TT
CLASS="FILENAME"
>cachelogd</TT
>
and <TT
CLASS="FILENAME"
>splitter</TT
> functionality are combined.</P
><P
> <TT
CLASS="FILENAME"
>splitter</TT
> is
a program to create fast word indexes using data collected by
<TT
CLASS="FILENAME"
>cached</TT
>. Those indexes are used later in search process.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHEMODE-START"
>5.2.4. Starting cache mode</A
></H2
><P
>To start "cache mode" follow these steps:</P
><P
></P
><OL
TYPE="1"
><LI
><P
>Start <TT
CLASS="FILENAME"
>cached</TT
> server:</P
><P
>					<KBD
CLASS="USERINPUT"
>cd /usr/local/dpsearch/sbin </KBD
></P
><P
><KBD
CLASS="USERINPUT"
>./cached  2&gt;cached.out &amp;</KBD
>
				</P
><P
>It will write some debug
information into <TT
CLASS="FILENAME"
>cached.out</TT
> file. <TT
CLASS="FILENAME"
>cached</TT
>
also creates a <TT
CLASS="FILENAME"
>cached.pid</TT
> file in /var directory of base
<SPAN
CLASS="APPLICATION"
>DataparkSearch</SPAN
> installation.</P
><P
><TT
CLASS="FILENAME"
>cached</TT
> listens to TCP
connections and can accept several indexers from different
machines. Theoretical number of indexers connections is equal to 128. In old mode <TT
CLASS="FILENAME"
>cached</TT
>
stores information sent by indexers in <TT
CLASS="FILENAME"
>/var/splitter/</TT
>
directory of <SPAN
CLASS="APPLICATION"
>DataparkSearch</SPAN
> installation. 
In new mode it stores in <TT
CLASS="FILENAME"
>/var/tree/</TT
> directory.</P
><P
>By default, <TT
CLASS="FILENAME"
>cached</TT
> starts in new mode. To run it in old mode, i.e. logs only mode, run it with
-l switch:</P
><P
><KBD
CLASS="USERINPUT"
>cached -l</KBD
></P
><P
>Or by specify <A
NAME="AEN3529"
></A
>
<B
CLASS="COMMAND"
>LogsOnly yes</B
> command in your <TT
CLASS="FILENAME"
>cached.conf</TT
>.</P
><P
>You can specify port for
<TT
CLASS="FILENAME"
>cached</TT
> to use without recompiling. In order to do that, please run</P
><P
>					<KBD
CLASS="USERINPUT"
>./cached -p8000 </KBD
>
				</P
><P
>where <TT
CLASS="LITERAL"
>8000</TT
> is the port number you choose.</P
><P
>You can as well specify a
directory to store data (it is <TT
CLASS="LITERAL"
>/var</TT
> directory by
default) with this command:</P
><P
>					<KBD
CLASS="USERINPUT"
>./cached -w /path/to/var/dir</KBD
>
				</P
></LI
><LI
><P
>Configure your <TT
CLASS="FILENAME"
>indexer.conf</TT
> as usual and for <B
CLASS="COMMAND"
>DBAddr</B
> command 
add <TT
CLASS="LITERAL"
>cache</TT
> as value of <TT
CLASS="LITERAL"
>dbmode</TT
> parameter and <TT
CLASS="LITERAL"
>localhost:7000</TT
>
as value of <TT
CLASS="LITERAL"
>cached</TT
> parameter (see <A
HREF="dpsearch-indexcmd.en.html#DBADDR_CMD"
>Section 3.10.2</A
>&#62;).
				</P
></LI
><LI
><P
>Run indexers. Several indexers
can be executed simultaneously. Note that you may install indexers on
different machines and then execute them with the same <TT
CLASS="FILENAME"
>cached</TT
>
server. This distributed system allows making indexing faster.</P
></LI
><LI
><P
>Flushing <SPAN
CLASS="APPLICATION"
>cached</SPAN
> buffers and url data, and creating cache mode limits.
To flush <SPAN
CLASS="APPLICATION"
>cached</SPAN
> buffers and url data and to create cache mode limits after indexing is done, send -HUP
signal to <TT
CLASS="FILENAME"
>cached</TT
>.
You can use <TT
CLASS="FILENAME"
>cached.pid</TT
> file to do this:</P
><P
><KBD
CLASS="USERINPUT"
>kill -HUP `cat /usr/local/dpsearch/var/cached.pid`</KBD
></P
><P
>N.B.: you needs wait till all buffers will be flushed before going to next step.</P
></LI
><LI
><P
>Creating word index. This stage is no needs, if 
<TT
CLASS="FILENAME"
>cached</TT
> runs in new, i.e. combined, mode.
 When some
information is gathered by indexers and collected in
<TT
CLASS="FILENAME"
>/var/splitter/</TT
> directory by <TT
CLASS="FILENAME"
>cached</TT
> it is possible
to create fast word indexes. <TT
CLASS="FILENAME"
>splitter</TT
> program is responsible for
this. It is installed in <TT
CLASS="FILENAME"
>/sbin</TT
> directory. Note
that indexes can be created anytime without interrupting current
indexing process.</P
><P
> Run <TT
CLASS="FILENAME"
>splitter</TT
> without any arguments:</P
><P
>							<KBD
CLASS="USERINPUT"
>/usr/local/dpsearch/sbin/splitter</KBD
>
						</P
><P
>It will take
sequentially all prepared files in
<TT
CLASS="FILENAME"
>/var/splitter/</TT
> directory and use them to build
fast word index. Processed logs in <TT
CLASS="FILENAME"
>/var/splitter/</TT
>
directory are truncated after this operation.</P
></LI
></OL
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHELOG-SEVSPL"
>5.2.5. Optional usage of several splitters</A
></H2
><P
>splitter has two command line arguments:
<TT
CLASS="LITERAL"
>-f [first file] -t [second file]</TT
> which allows
limiting used files range. If no parameters are specified splitter
distributes all prepared files. You can limit files range using
-f and -t keys specifying parameters in HEX notation. For example,
<TT
CLASS="LITERAL"
>splitter -f 000 -t A00</TT
> will create word indexes
using files in the range from 000 to A00. These keys allow using
several splitters at the same time. It usually gives more quick
indexes building. For example, this shell script starts four splitters
in background:</P
><PRE
CLASS="PROGRAMLISTING"
>#!/bin/sh
splitter -f 000 -t 3f0 &amp;
splitter -f 400 -t 7f0 &amp;
splitter -f 800 -t bf0 &amp;
splitter -f c00 -t ff0 &amp;</PRE
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHELOG-RUNSPL"
>5.2.6. Using run-splitter script</A
></H2
><P
>There is a <TT
CLASS="FILENAME"
>run-splitter</TT
>
script in <TT
CLASS="FILENAME"
>/sbin</TT
> directory of <SPAN
CLASS="APPLICATION"
>DataparkSearch</SPAN
>
installation. It helps to execute subsequently all three indexes
building steps.</P
><P
>"run-splitter" has these two command line parameters:</P
><P
>			<KBD
CLASS="USERINPUT"
>run-splitter --hup --split</KBD
>
		</P
><P
>or a short version:</P
><P
>			<KBD
CLASS="USERINPUT"
>run-splitter -k -s</KBD
>
		</P
><P
>Each parameter activates corresponding indexes
building step. <TT
CLASS="FILENAME"
>run-splitter</TT
> executes all three
steps of index building in proper order:</P
><P
></P
><OL
TYPE="1"
><LI
><P
>Sending -HUP signal to
cached. <TT
CLASS="LITERAL"
>--hup</TT
> (or <TT
CLASS="LITERAL"
>-k</TT
>)
run-splitter arguments are responsible for this.</P
></LI
><LI
><P
>Running splitter. Keys <TT
CLASS="LITERAL"
>--split</TT
>  (or <TT
CLASS="LITERAL"
>-s</TT
>).</P
></LI
></OL
><P
>In most cases just run <B
CLASS="COMMAND"
>run-splitter</B
> script
with all <TT
CLASS="LITERAL"
>-k -s</TT
> arguments. Separate usage of those
three flags which correspond to three steps of indexes building is
rarely required. </P
><P
><B
CLASS="COMMAND"
>run-splitter</B
> have optional parameters: <TT
CLASS="LITERAL"
>-p=n</TT
> and <TT
CLASS="LITERAL"
>-v=m</TT
>
to specify pause in seconds after each log buffer update and verbose level respectively.
<TT
CLASS="LITERAL"
>n</TT
> is seconds number (default value: 0), <TT
CLASS="LITERAL"
>m</TT
> is verbosity level (default value: 4).</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="CACHELOG-SEARCH"
>5.2.7. Doing search</A
></H2
><P
>To start using <B
CLASS="COMMAND"
>search.cgi</B
> in the "cache mode",
edit as usually your <TT
CLASS="FILENAME"
>search.htm</TT
> template and add the "cache" as value of <TT
CLASS="LITERAL"
>dbmode</TT
> parameter of
<B
CLASS="COMMAND"
>DBAddr</B
> command.

		</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="LIMITS"
>5.2.8. Using search limits</A
></H2
><P
><A
NAME="AEN3627"
></A
>
To use search limits in cache mode, you should add appropriate
<TT
CLASS="LITERAL"
>Limit</TT
> command(s) to your <TT
CLASS="FILENAME"
>indexer.conf</TT
> 
(or <TT
CLASS="FILENAME"
>cached.conf</TT
>, if <B
CLASS="COMMAND"
>cached</B
> is used) and to <TT
CLASS="FILENAME"
>search.htm</TT
>
or <TT
CLASS="FILENAME"
>searchd.conf</TT
> (if <TT
CLASS="LITERAL"
>searchd</TT
> is used).
<PRE
CLASS="SYNOPSIS"
>Limit prm:type [SQL-Request [DBAddr]]</PRE
></P
><P
>To use, for example, search limit by tag, by category and by site, add follow lines to
<TT
CLASS="FILENAME"
>search.htm</TT
> or to <TT
CLASS="FILENAME"
>indexer.conf</TT
>
(<TT
CLASS="FILENAME"
>searchd.conf</TT
>, if <TT
CLASS="LITERAL"
>searchd</TT
> is used).</P
><PRE
CLASS="PROGRAMLISTING"
>Limit t:tag
Limit c:category
Limit site:siteid</PRE
><P
>where <TT
CLASS="LITERAL"
>t</TT
> - name of CGI parameter (&amp;t=) for this
constraint, <TT
CLASS="LITERAL"
>tag</TT
> - type of constraint.</P
><P
>Instead of tag/category/siteid in example above you can use any of values from table below:
<DIV
CLASS="TABLE"
><A
NAME="AEN3648"
></A
><P
><B
>Table 5-1.  Cache mode predefined limit types</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><TBODY
><TR
><TD
>category</TD
><TD
>Category limit.</TD
></TR
><TR
><TD
>tag</TD
><TD
>Tag limit.</TD
></TR
><TR
><TD
>time</TD
><TD
>Time limit (a hour precision).</TD
></TR
><TR
><TD
>language</TD
><TD
>Language limit.</TD
></TR
><TR
><TD
>content</TD
><TD
>Content-Type limit.</TD
></TR
><TR
><TD
>siteid</TD
><TD
>url.site_id limit.</TD
></TR
><TR
><TD
>link</TD
><TD
>Limit by pages what links to url.rec_id specified.</TD
></TR
><TR
><TD
>hostname (obsolete)</TD
><TD
>Hostname (url) limit. This limit is obsolete and should be replaced by site_id limit</TD
></TR
></TBODY
></TABLE
></DIV
></P
><P
>If the second, optional, parameter <CODE
CLASS="OPTION"
>SQL-Request</CODE
> is specified for <B
CLASS="COMMAND"
>Limit</B
> command, then this SQL-query is executed for limit construction. 
This SQL-query should return all possible pairs of limit value and url.rec_id. E.g.:
<PRE
CLASS="PROGRAMLISTING"
>Limit prm:strcrc32 "SELECT label, rec_id FROM labels" pgsql://u:p@localhost/sitedb/</PRE
>
where prm - is the name of limit and the name of CGI-parameter is used for this limit; strcrc32 - is the type of limit, particularly for this limit is a string. 
Instead of strcrc32 it's possible to use any of the following limit types:
<DIV
CLASS="TABLE"
><A
NAME="AEN3680"
></A
><P
><B
>Table 5-2. SQL-based cache mode limit types</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><TBODY
><TR
><TD
>hex8str</TD
><TD
>Hex or hexavigesimal (base-26) string similar to those used in categories. The nested limit will be created.</TD
></TR
><TR
><TD
>strcrc32</TD
><TD
>A string, the hash32 value is calculated on, used as key for this limit.</TD
></TR
><TR
><TD
>int</TD
><TD
>An integer (4-byte wide).</TD
></TR
><TR
><TD
>hour</TD
><TD
>An integer (4-byte wide) number of seconds since epoch. The value in index is in hour precision.</TD
></TR
><TR
><TD
>minute</TD
><TD
>An integer (4-byte wide) number of seconds since epoch. The value in index is in minute precision.</TD
></TR
></TBODY
></TABLE
></DIV
></P
><P
>With third, optional, parameter <CODE
CLASS="OPTION"
>DBAddr</CODE
> for <B
CLASS="COMMAND"
>Limit</B
> command it's possible to specify a connection to an alternate SQL-database where to get data for this limit.</P
><P
>It's possible to omit optional parameters <CODE
CLASS="OPTION"
>SQL-Request</CODE
> and <CODE
CLASS="OPTION"
>DBAddr</CODE
> of <B
CLASS="COMMAND"
>Limit</B
> command in search template <TT
CLASS="FILENAME"
>search.htm</TT
> or in <TT
CLASS="FILENAME"
>searchd.conf</TT
> file (when <B
CLASS="COMMAND"
>searchd</B
> is used), since they are used only for limit construction.
<PRE
CLASS="PROGRAMLISTING"
>Limit prm:strcrc32</PRE
></P
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